Yesterday a sewerage leak forced the Department of Environmental Management (DEM) to enact a temporary closure of upper Narragansett Bay to shellfishers beginning at noon. The area includes the Conimicut Triangle and Area A, and was closed due to a leak from the Narragansett Bay Commission’s (NBC) wastewater collection system in Pawtucket.

“There appears to have been a blockage which led to an overflow,” said Jamie Samons, public affairs director for the Commission.

NBC is unsure how much raw sewerage leaked first into the Seekonk River, and then into the Bay.

“We don’t know,” said Samons. “We don’t know how long it was leaking.”

A release from the DEM cited the amount as “significant but unknown.”

The leak was discovered by NBC employees at 8 a.m. yesterday morning and was repaired by 8:25. NBC said the problem was an “accumulation of rags and grease on the regulator screen.”

Jonathan Stone, executive director at Save the Bay, said the blockage is an important reminder to not dump dangerous substances and objects down drains.

“Anything you put on the street or directly into drains is going to end up in Narragansett Bay,” he said.

“It shows the importance of not putting grease down the drain,” said Samons.

Stone noted that there are chemicals much more dangerous than grease that can leach into the Bay if people are not careful.

“People need to be constantly aware,” he said. “It shows how vulnerable the Upper Bay is to the urbanized landscape.”

Once the leak was detected, crews went to work to remove the blockage and stop the overflow. They then began an emergency disinfection with chlorine.

Tim McGiveney, co-owner of Twin Shellfish, said temporary closures like yesterday’s are more of a nuisance than a major problem.

“We still have areas to work in,” said McGiveney yesterday. “Today we bought everything from Area 2.”

McGiveney said the closure didn’t affect regular business.

Samons said this type of blockage and overflow doesn’t occur very often because of routine maintenance checks.

Gail Mastrati, spokeswoman for the Rhode Island DEM, said the last time a non-weather related overflow occurred was in August of 2011. She said it is difficult to tell whether these occurrences have been happening more or less frequently in recent years.

“They happen from time to time,” she said.

Though NBC was unsure how long the leak lasted yesterday, they were able to remedy the problem in a short amount of time.

“It was a relatively quick fix,” she said.

“The agency did a great job of responding quickly,” said Stone about NBC. “It’s remarkable how quickly they were able to address the problem.